龙岗西地区首口非常规超深井钻井技术

Drilling technology for the first unconventional ultra-deep well in West Longgang Region

谭茂波 何世明 邓传光 米光勇 高德伟 王强

TAN Maobo HE Shiming DENG Chuanguang MI Guangyong GAO Dewei WANG Qiang

西南石油大学石油与天然气工程学院，四川成都　610500 西南石油大学油气藏地质及开发工程国家重点实验室，四川成都　610500 中国石油西南油气田公司勘探事业部，四川成都　610041 中国石油西南油气田公司川西北气矿，四川江油　620041

Petroleum and Gas Engineering Colleg, Southwest Petroleum University, Chengdu 610500, China State Key Laboratory of Oil & Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China Exploration Division of Southwest Oil & Gas Field Company, CNPC, Chengdu 610041, China Northwestern Sichuan Gasfield District of Southwest Oil & Gas Field Company, CNPC, Jiangyou 620041, China

龙岗61 井是四川盆地龙岗西地区第1 口非常规超深井，完钻井深6 618 m。侏罗系地层井壁稳定性差，纵向上压力系统复杂，深部海相地层H2S 含量超过30 g/m3、同时存在异常超高压CO2 气层和盐水层，井底压力超过110 MPa、温度在150 ℃以上。为此，龙岗61 井采取了如下钻井技术措施：采用6 开制非常规套管层序封隔不同复杂层段，有效预防和控制井下地质风险；在蓬莱镇—沙溪庙组易漏地层应用空气钻井防漏治漏、防斜快打；对自流井组和须家河组强研磨性地层优化钻头设计，并在小井眼段进行PDC 钻头提速试验；优化抗高温聚磺水基钻井液，使之具备较强的抗高温、抗盐及抗钙污染能力。实践表明，龙岗61 井非常规超深井钻井技术不仅有效解决了复杂地层所带来的钻井难题，实现安全快速钻至目的层，而且还在川渝地区超深井钻井技术上得到创新，形成了一套较完整的非常规超深井钻井技术。

Well Longgang-61 is the first unconventional ultradeep well in West Longgang Region in Sichuan Basin with a total depth of 6 618 m. The Jurassic wellbore wall is poor in stability; the vertical pressure system is complex; the H2S content in deep marine formation is over 30 g/m3; there also exists CO2 zone and brine zone with abnormally high pressure; the bottom hole pressure is over 110 MPa and the temperature is over 150 ℃. For this reason, Well Longgang-61 adopted the following drilling techniques: using 6-spud system and unconventional casing program to isolate various complex intervals, effectively preventing and controlling downhole geologic risks; using air drilling in leakage-prone formations in Penglai Town-Shaxi Temple Formation to prevent fluid loss and prevent deviation and ensure fast drilling; for formations with strong abrasivity in Ziliujing Formation and Xujiahe Formation, the drilling bit desing was optimized and accelerating test was performed for PDC drilling bit in slim hole section; and optimizing high temperature poly-suphonated water-based drilling fluid so as to provide it with strong capability in resistance to high temperature, salt and calcium. Practice shows that the drilling technology for unconventional ultra-deep well Longgang-61 not only addressed the drilling difficulty caused by formation complexity and realized safe and fast drilling to the target zone, but it was innovated in drilling of ultra-deep wells in Sichuan and Qiongchong areas, creating a set of complete drilling technologies for ultra-deep wells.

10.13639/j.odpt.2015.02.006